2015 Accord intermittent start problem
 

My 2015 EXL V6 coupe refused to start about a month ago. As battery was just past expiration, I replaced it and things were great for a month or so. Yesterday, when start button was pushed, just a single 'click' (as before) and no start although accessories were on. Tried to jump it off but with a new battery I didn't think this was the cause. I tried starting maybe 10 times yesterday with no luck. I set up an appointment yesterday and scheduled a tow to the shop. Today, the car started right up. Called the shop and it was confirmed that of course, they could not troubleshoot if the problem was gone, so cancelled shop and tow. I checked for OBD codes being thrown and there were none. All systems checked good!

One strange thing I did notice was when the car is working properly, when I depress the brake prior to starting, it feels normal and allows maybe an inch of travel, then starts. When this lousy issue is present, the brake feels like it's locked up and has NO travel.

Any thoughts on this? An undependable car is like not having a car, very un-Honda like.

If the brake switch is not applied it will not start. Look at the brakes.

The stiff brakes prevent the brake lever from registering that the brake is depressed. This then tells the ECM not to start the engine.
There are several things that can cause stiff brakes.
Clogged brake lines or hoses, faulty brake booster, leaky vacuum lines, ABS modulator, seized caliper, etc
If you have stiff brakes and the engine doesn't start
Then try manipulating the brake switch with your hands and see if that helps???

Avisitor,
I think you're on to something. I also think the braking system may be the root cause. However, IMHO because the car is either totally normal or just a 'click' and dead this would indicate that - Clogged brake lines or hoses, faulty brake booster, leaky vacuum lines, ABS modulator, seized caliper could not possibly be the problem. Understand that the first thing I always do when butt hits seat is depress the brake. But what could cause the brake pedal to seem frozen in place when the car doesn't start and feel normal when it does start? It almost seems mechanically locked.

Each vehicle can have different issues with the brakes. Not really sure. People come here and post their issues. Some try to help. But, other do not come back with their solutions. So, sorry I can not help more. May be a search of the internet might help??

Update: After talking to some smart people (never saw my car), they feel that I may either have a sticky brake booster check valve or the vacuum pressure sensor may be bad.
Any thoughts on this?

It is a good place to start checking

Throw a check valve in the booster. Cheap and easy to do. May very well be your problem.

Problem solved, Honda is (hopefully) cured.

On 9/21, my Honda officially died. It had been not starting (clicking) and the immediately started. This lasted until 9/21. The car was dead all day, so I had it towed to the repair shop and asked them to check OBD for any thrown codes. They did and it told them the issue was the starter. A forum responder suggested this earlier but as it was sporadically starting and running, I discounted the suggestion. Being an old guy, in my mind a starter was either good… or bad. Evidently, newer cars have starters that can be intermittent which was news to me. Regardless, the shop replaced the starter and the car has run flawlessly since. Fingers crossed.

I'm old as well. Didn't you learn to hit the starter with a hammer to get them to work? The brushes will be intermittent until they don't work at all. Starters are still starters.